Third John is probably the most personal letter in the New Testament. Most of the epistles originally went, of course, to churches or groups of Christians. First and 2 John are both of this type. The Pastoral Epistles, while sent to specific individuals, namely, Timothy and Titus, were obviously written with a wide circulation in mind as well. Philemon, too, gives evidence that Paul intended its recipient to share it with the church that met in his house. Third John also has universal value, and the early Christians recognized that it would benefit the whole Christian church. However the content of this letter is very personal.
". . . 3 John shows independence from epistolary conventions found elsewhere in the NT (including 2 John), and conforms most closely to the secular pattern of letter-writing in the first century A.D. . . . In 3 John this includes a greeting with a health-wish; and expression of joy at news of the addressee's welfare; the body of the letter, containing the promise of another epistle; and, at the close, greetings to and from mutual friends (cf. the papyri)."1
The author was evidently the Apostle John who identified himself as "the elder"here (v. 1) as he did in 2 John. The striking similarity in content, style, and terminology in these two epistles confirms the ancient tradition that John wrote both of them.
Since there is no internal evidence concerning where Gaius lived most interpreters have placed him in the Roman province of Asia, the most probable destination of 1 and 2 John. His name was a common one in the Greek world.
The process of establishing a date for the writing of 3 John has been deductive as well. Probably John wrote this epistle about the same time he wrote 1 and 2 John, A.D. 90-95, and from Ephesus.
